Conventionally, as a display supporting device for use with a personal computer (hereinafter referred to as “PC”) and a television receiver, a supporting device 100 for a liquid crystal monitor as shown in FIG. 12 is known. As shown in FIG. 12, this supporting device 100 includes: a base portion 101; a supporter 102 installed on and directed upward from this base portion 101; an elevator 103 installed in, and allowed to move up and down relative to, this supporter 102; and a movable unit 104 that is installed on an upper portion of this elevator 103, tiltably about a support shaft 103a in directions indicated by arrows Y2 in FIG. 12.
A helical spring 102a is contained inside the supporter 102, and by this helical spring 102a, the elevator 103 is pressed in an upward direction (indicated by an arrow Y1 in FIG. 12). An attachment 104a to which a display D is to be attached is provided on the movable unit 104, and by this attachment 104a, the display D is held rotatably in directions indicated by an arrow Y3 in FIG. 12.
According to such a supporting device 100, the elevator 103 can be slid upwardly and downwardly relative to the supporter 102, and the height of the display D can be changed so as to suit the preference of a user. At that time, since the elevator 103 is being pressed in the upward direction (as indicated by the arrow Y1 in FIG. 12) by the helical spring 102a, the operation for moving the display D in the upward direction can be smoothly performed with a light operation force (for example, refer to Japanese Utility Model Registration No. 3063920, pages 6 and 7, FIG. 1 and FIG. 2).
However, the conventional supporting device 100 has the following known problems. Since the supporting device 100 uses the helical spring 102a as a pressing force applying means, the pressing force would correspond to the height of the elevator 103 (the compression state of the spring). For this reason, the operation feeling at the time of the raising adjustment would correspond to the compression state of the spring and could not be adjusted to the operation feeling fit to the preference of the user.
Also, the operation feeling at the time of the raising adjustment could not be made constant, irrespective of the height of the elevator 103. For example, the raising operation force required when the display D is located at a higher position is stronger than that required when the display D is located at a lower position.
With this in view, as a countermeasure for making the operation feeling at the time of the raising adjustment constant, the use of a spiral spring instead of the helical spring 102a could be conceived. Generally speaking, although the pressing force of the spiral spring is constant as compared with the helical spring, the pressing force is still not strictly uniform irrespective of the unwound quantity; as the unwound quantity is increased, the pressing force is made stronger nevertheless. For this reason, even if the spiral spring is employed instead of the helical spring 102a, when the elevator 103 is located at a lower position, the unwound quantity of the spiral spring becomes greater, which would quite likely increase the pressing force. Thus, this countermeasure cannot make the operation feeling at the time of the raising adjustment constant.
Considering the universal applicability of the supporting device 100, it would be advantageous that a single type of the supporting device 100 is designed to be usable for various types of display D. However, when the displays D that may be different in production weight from one model to another are supported equally by the same type of supporting device 100, there is a fear that the operation feeling at the time of the raising adjustment is different for each model. For this reason, the necessity of taking a countermeasure, such as preparation of the helical spring 102a adjusted for each model, would arise, which increases the cost accordingly.